This is a recently uncovered Mac OS Snow Leopard beta ISO dating from October 2008 in the development cycle. It is (as of 5/1/2020) the latest known bootable build for PowerPC. Not much is known in the way of what does and doesn't work, other than this being a confirmed working build of Mac OS Snow Leopard for PowerPC, prior to this code being stripped from the OS in February 2009. If you would like more information on this subject, please visit the following website. There have been multiple examples of success with the recently uncovered beta builds.
Note: This specific ISO is not immediately bootable on PPC prior to some modification. Instructions for modification are provided on the Macrumors site, and will also be published as a separate downloadable file here, too.